Setting a list of enabled named groups
If the default list of enabled named groups is inadequate for your application, you can use the
jdk.tls.namedGroups system property to specify an additional list of named groups.
The following list shows the named groups that are enabled by default.
The
named groups that were enabled by default in service refresh 6 and later refreshes:// recommended
x25519 (29)
secp256r1 (23)
secp384r1 (24)
secp521r1 (25)
x448 (30)
ffdhe2048 (256)
ffdhe3072 (257)
ffdhe4096 (258)
ffdhe6144 (259)
ffdhe8192 (260)
X25519MLKEM768 (4588)
Notes:
Support for ffdhe3072,ffdhe4096,ffdhe6144, andffdhe8192requires the IBMJCEPlus or the IBMJCEPlusFIPS providers.
Support for x25519andx448requires the IBMJCEPlus provider.
Support for X25519MLKEM768requires the IBMJCEPlus provider.

The named groups that were enabled by default before service refresh
6:
// recommended
secp256r1 (23)
secp384r1 (24)
secp521r1 (25)
// NIST curves
sect283k1 (9)
sect283r1 (10)
sect409k1 (11)
sect409r1 (12)
sect571k1 (13)
sect571r1 (14)
// Non-FIPS curves
secp256k1 (22)Additional named groups can be specified by setting the
jdk.tls.namedGroups
system property. For
example:jdk.tls.namedGroups="secp521r1,secp256r1
,ffdhe2048
"The
values for named groups must be separated with a comma. If the system property is not defined or the
value is empty, the default named groups and preferences are used.